Superconductivity due to fluctuating loop currents.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38875341.
- Also identified by DOI 10.1126/sciadv.adn3662 and PMC identifier 11177937.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Orbital magnetism and the loop currents (LCs) that accompany it have been proposed to emerge in many systems, including cuprates, iridates, and kagome superconductors. In the case of cuprates, LCs have been put forward as the driving force behind the pseudogap, strange-metal behavior, and <i>d</i><sub><i>x</i><sup>2</sup>-<i>y</i><sup>2</sup></sub>-wave superconductivity. Here, we investigate whether fluctuating intra-unit-cell LCs can cause unconventional superconductivity. For odd-parity LCs, we find that they are repulsive in all pairing channels near the underlying quantum-critical point (QCP). For even-parity LCs, their fluctuations give rise to unconventional pairing, which is not amplified in the vicinity of the QCP, in sharp contrast to pairing mediated by spin-magnetic, nematic, or ferroelectric fluctuations. Applying our formalism to the cuprates, we conclude that fluctuating intra-unit-cell LCs are unlikely to yield <i>d</i><sub><i>x</i><sup>2</sup>-<i>y</i><sup>2</sup></sub>-wave superconductivity. If LCs are to be relevant for the cuprates, they must break translation symmetry.